<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>ES6 map-set</title>
</head>
<body>
<script>

    const m = new Map();
    const o = {p: 'hello map'};
    //console.log(o.p); //hello map

    m.set(o, 'content');
    m.get(o);//content

    console.log(m.get(o));


</script>
</body>
</html>